| 1 | #ifndef HEALTH_INTERNAL_H |
| 2 | #define HEALTH_INTERNAL_H |
| 3 | |
| 4 | /* |
| 5 | * Copyright (C) 2012 David Goulet <dgoulet@efficios.com> |
| 6 | * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 7 | * |
| 8 | * SPDX-License-Identifier: GPL-2.0-only |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <assert.h> |
| 13 | #include <common/compat/time.h> |
| 14 | #include <pthread.h> |
| 15 | #include <urcu/tls-compat.h> |
| 16 | #include <urcu/uatomic.h> |
| 17 | #include <urcu/list.h> |
| 18 | #include <lttng/health.h> |
| 19 | #include <common/macros.h> |
| 20 | |
| 21 | /* |
| 22 | * These are the value added to the current state depending of the position in |
| 23 | * the thread where is either waiting on a poll() or running in the code. |
| 24 | */ |
| 25 | #define HEALTH_POLL_VALUE (1UL << 0) |
| 26 | #define HEALTH_CODE_VALUE (1UL << 1) |
| 27 | |
| 28 | #define HEALTH_IS_IN_POLL(x) ((x) & HEALTH_POLL_VALUE) |
| 29 | |
| 30 | struct health_app; |
| 31 | |
| 32 | enum health_flags { |
| 33 | HEALTH_ERROR = (1U << 0), |
| 34 | }; |
| 35 | |
| 36 | struct health_state { |
| 37 | /* |
| 38 | * last counter and last_time are only read and updated by the health_check |
| 39 | * thread (single updater). |
| 40 | */ |
| 41 | unsigned long last; |
| 42 | struct timespec last_time; |
| 43 | |
| 44 | /* |
| 45 | * current and flags are updated by multiple threads concurrently. |
| 46 | */ |
| 47 | unsigned long current; /* progress counter, updated atomically */ |
| 48 | enum health_flags flags; /* other flags, updated atomically */ |
| 49 | int type; /* Indicates the nature of the thread. */ |
| 50 | /* Node of the global TLS state list. */ |
| 51 | struct cds_list_head node; |
| 52 | }; |
| 53 | |
| 54 | enum health_cmd { |
| 55 | HEALTH_CMD_CHECK = 0, |
| 56 | }; |
| 57 | |
| 58 | struct health_comm_msg { |
| 59 | uint32_t cmd; /* enum health_cmd */ |
| 60 | } LTTNG_PACKED; |
| 61 | |
| 62 | struct health_comm_reply { |
| 63 | uint64_t ret_code; /* bitmask of threads in bad health */ |
| 64 | } LTTNG_PACKED; |
| 65 | |
| 66 | /* Declare TLS health state. */ |
| 67 | extern DECLARE_URCU_TLS(struct health_state, health_state); |
| 68 | |
| 69 | /* |
| 70 | * Update current counter by 1 to indicate that the thread entered or left a |
| 71 | * blocking state caused by a poll(). If the counter's value is not an even |
| 72 | * number (meaning a code execution flow), an assert() is raised. |
| 73 | */ |
| 74 | static inline void health_poll_entry(void) |
| 75 | { |
| 76 | /* Code MUST be in code execution state which is an even number. */ |
| 77 | assert(!(uatomic_read(&URCU_TLS(health_state).current) |
| 78 | & HEALTH_POLL_VALUE)); |
| 79 | |
| 80 | uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE); |
| 81 | } |
| 82 | |
| 83 | /* |
| 84 | * Update current counter by 1 indicating the exit of a poll or blocking call. |
| 85 | * If the counter's value is not an odd number (a poll execution), an assert() |
| 86 | * is raised. |
| 87 | */ |
| 88 | static inline void health_poll_exit(void) |
| 89 | { |
| 90 | /* Code MUST be in poll execution state which is an odd number. */ |
| 91 | assert(uatomic_read(&URCU_TLS(health_state).current) |
| 92 | & HEALTH_POLL_VALUE); |
| 93 | |
| 94 | uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE); |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Update current counter by 2 indicates progress in execution of a |
| 99 | * thread. |
| 100 | */ |
| 101 | static inline void health_code_update(void) |
| 102 | { |
| 103 | uatomic_add(&URCU_TLS(health_state).current, HEALTH_CODE_VALUE); |
| 104 | } |
| 105 | |
| 106 | /* |
| 107 | * Set health "error" flag. |
| 108 | */ |
| 109 | static inline void health_error(void) |
| 110 | { |
| 111 | uatomic_or(&URCU_TLS(health_state).flags, HEALTH_ERROR); |
| 112 | } |
| 113 | |
| 114 | struct health_app *health_app_create(int nr_types); |
| 115 | void health_app_destroy(struct health_app *ha); |
| 116 | int health_check_state(struct health_app *ha, int type); |
| 117 | void health_register(struct health_app *ha, int type); |
| 118 | void health_unregister(struct health_app *ha); |
| 119 | |
| 120 | #endif /* HEALTH_INTERNAL_H */ |